Evaluation of standard enrichment broths for recovery of healthy and chlorine-injured Escherichia coli O157:H7 cells in kimchi.

This study aimed to evaluate three standard enrichment broth preparations for the recovery of healthy and chlorine-injured E. coli O157:H7 cells in kimchi. The growth of healthy and chlorine-injured cells in kimchi was observed in three different broths for 24 h. Results showed that the three broths were equally effective for the growth of healthy cells, although the broth described by the International Organization for Standardization (ISO) showed better performance in terms of maximum growth rate when compared to the other two broths described by the Korea Food Code (KFC) and the Food and Drug Administration (FDA). In the case of chlorine-injured cells, similar growth patterns were observed in KFC and ISO broths, whereas inhibition or no growth was found in FDA broth. Thus, this study suggests that KFC and ISO broths were more suitable than FDA broth for the enrichment of E. coli O157:H7 cells in kimchi.

Molecular epidemiology and antimicrobial susceptibility of Clostridium difficile isolates from two Korean hospitals.

Clostridium difficile is one of the main etiological agents causing antibiotic-associated diarrhea. This study investigated the genetic diversity of 70 toxigenic C. difficile isolates from two Korean hospitals by employing toxinotyping, ribotyping, multilocus sequence typing (MLST), and pulsed-field gel electrophoresis (PFGE). Toxin gene amplification resulted in 68 A⁺B⁺ and two A-B+ isolates. Most isolates (95.7-100%) were susceptible to daptomycin, metronidazole, and vancomycin. Seventy C. difficile isolates were classified into five toxinotypes, 19 ribotypes, 16 sequence types (STs), and 33 arbitrary pulsotypes. All C. difficile isolates of ribotype 018 (n = 38) were classified into ST17, which was the most prevalent ST in both hospitals. However, C. difficile isolates of ST17 (ribotype 018) exhibited pulsotypes that differed by hospital. ST2 (ribotype 014/020), 8 (ribotypes 002), 17 (ribotype 018), and 35 (ribotypes 015) were detected in both hospitals, whereas other STs were unique to each hospital. Statistical comparison of the different typing methods revealed that ribotyping and PFGE were highly predictive of STs. In conclusion, our epidemiological study indicates that C. difficile infections in both hospitals are associated with the persistence of endemic clones coupled with the emergence of many unique clones. A combination of MLST with PFGE or ribotyping could be useful for monitoring epidemic C. difficile strains and the emergence of new clones in hospitals.

Clarifying the transmission route of Staphylococcus aureus colonizing the skin in early childhood atopic dermatitis.

BACKGROUND: We previously found that skin-colonizing Staphylococcus aureus in early childhood atopic dermatitis (AD) originates predominantly from the patient's nose, whereas maternal transmission did not contribute substantially to colonization. OBJECTIVE: To investigate the transmission route and definitive source of skin-colonizing S aureus in early childhood AD. METHODS: A total of 527 children and 32 healthy teachers from 2 kindergartens and 1 elementary school were included in the study. Children were screened for AD and categorized into 3 groups (AD, borderline, and healthy). Samples were collected from 5 to 6 different body sites, including the skin, subungual spaces, and anterior nares. The identity of colonies apparent on mannitol salt agar plates was confirmed by polymerase chain reaction amplification of the nuc gene. The genotypic composition of cultured isolates was examined by pulsed-field gel electrophoresis and analyzed with a dendrogram. RESULTS: The total colonization rate was higher in the AD group (34.6%) than in the borderline (21.1%) and healthy groups (25.4%). In the AD group, S aureus was more frequently cultured from the subungual areas (30.8%) than the anterior nares (19.2%). To assess self-contamination or recolonization, dendrogram analysis revealed that most isolate pairs (22/23) had the same pulsed-field gel electrophoresis pattern. CONCLUSION: As with the anterior nares, the subungual spaces are important reservoir of skin-colonizing S aureus in early childhood AD. The transmission route for self-contamination or recolonization of S aureus appears to be from children's anterior nares to the skin through their own fingers. Child-to-child and/or teacher-to-child transmission in a classroom do not seem to be definite routes of S aureus transmission.

Associations among organochlorine pesticides, Methanobacteriales, and obesity in Korean women.

BACKGROUND: Although Methanobacteriales in the gut has recently been linked to obesity, no study has examined the hypothesis that waist circumference, a marker of visceral obesity, are positively associated with Methanobacteriales in the general population. Since Methanobacteriales increase in a petroleum-contaminated environment to biodegrade petroleum as one way of autopurification, we also hypothesized that high body burden of highly lipophilic petroleum-based chemicals like organochlorine pesticides (OCPs) is associated with higher levels of Methanobacteriales in the gut. METHODOLOGY/PRINCIPAL FINDINGS: Among 83 Korean women who visited a community health service center for a routine health checkup, quantitative real-time PCR (qPCR) based on 16S rDNA was used to quantify Methanobacteriales in feces. Nine OCPs were measured in both serum and feces of 16 subjects. Methanobacteriales were detected in 32.5% (27/83 women). Both BMI and waist circumference among women with Methanobacteriales were significantly higher than in women without Methanobacteriales (P = 0.04 and P = 0.01, respectively). Also, Methanobacteriales levels in feces were positively associated with BMI and waist circumference (r = +0.23 and P = 0.03 for both). Furthermore, there were significant correlations between feces Methanobacteriales levels and serum concentrations of most OCPs, including with cis-nonachlor (r = +0.53, P<0.05), oxychlordane (r = +0.46, P<0.1), and trans-nonachlor (r = +0.43, P<0.1). Despite high correlations of serum and feces concentrations of most OCPs, feces OCP concentrations were not clearly associated with feces Methanobacteriales levels. CONCLUSION/SIGNIFICANCE: In this cross-sectional study, the levels of Methanobacteriales in the human gut were associated with higher body weight and waist circumference. In addition, serum OCP concentrations were positively correlated with levels of Methanobacteriales. There may be a meaningful link among body burden of OCP, Methanobacteriales in the gut, and obesity in the general population.

Measuring comprehensive outcomes in palliative care: validation of the Korean version of the Good Death Inventory.

CONTEXT: No systematic or comprehensive attempts have yet been made to assess quality of death as an indicator of palliative care outcomes in Korea, and no validated instruments exist for the assessment of a good death in Koreans. OBJECTIVES: This study examined the validity and reliability of the Korean version of the Good Death Inventory (GDI), which was developed in Japan to evaluate the quality of death from the perspective of bereaved family members. METHODS: Forward and backward translations and a pilot test were conducted. In a multicenter cross-sectional survey, a questionnaire packet, including the GDI, overall quality of life during the last week, and overall satisfaction with care, was mailed to bereaved family members (n=501) of patients who had died from cancer two to six months before the study. Descriptive analyses were performed, including response rate, mean, median, skewness, and kurtosis for each item. The reliability of the GDI was tested by Cronbach's alpha. The dimensional structure was assessed using confirmatory factor analyses. Concurrent validity was tested by correlation with the overall quality of life and overall satisfaction with care. RESULTS: Participants were able to complete the GDI, and the compliance rates were satisfactory. Cronbach's alpha coefficient for internal consistency was 0.93 overall and ranged from 0.69 to 0.94 for subdomains. The hypothesized 18-factor model of a good death appeared to fit the data (goodness of fit index [GFI]=0.964; adjusted GFI index=0.960; normal fit index=0.952). The overall scores on the GDI correlated with patients' quality of life (0.56; P<0.001) and overall satisfaction with care (0.44; P<0.001). CONCLUSION: The Korean version of the GDI is a reliable and valid measure of the comprehensive outcomes of palliative care from the perspective of bereaved Korean family members.

Epitope analysis of PPARgamma monoclonal antibody Pgamma48.34A and its application for screening PPARgamma ligands.

Peroxisome proliferator-activated receptors (PPARs) are transcription factors that directly modulate gene expression by binding to specific ligands. It has been established that PPARgamma ligands play an essential role in obesity, diabetes, and inflammation. Recently, a great deal of research has focused on the screening of PPARgamma ligands. In this study, both a human peroxisome proliferator-activated receptors gamma2 (PPARgamma2) recombinant protein and a specific monoclonal antibody against PPARgamma2 were produced in order to screen PPARgamma ligands. Analysis of deletion mutants revealed that monoclonal anti-PPARgamma antibody Pgamma48.34A possesses an antigenic determinant in the N-terminal region (31-84 a.a) of human PPARgamma2. The results of Western blot testing revealed that Pgamma48.34A recognized both glutathione S-transferase (GST)- and his-tagged human and mouse PPARgamma recombinant proteins and also identified PPARgamma in adipocytes and mouse tissues. Compared to some commercially available antibodies, this antibody does not bind with skimmed milk or BSA and exhibits a higher degree of specificity. An in vitro binding assay revealed that PPARgamma2 was bound to steroid receptor coactivator-1 (SRC-1) in a dose-responsive manner in the presence of indomethacin, and Pr48.34A was able to detect PPARgamma in a complex consisting of PPARgamma and SRC-1. Using Pgamma48.34A antibody, an enzyme-linked immunosorbent assay (ELISA) system based on the binding between fPPARgamma2 and SRC-1 has been optimized to screen new PPARgamma ligands. This new antibody, Pgamma48.34A, exhibits higher degrees of both specificity and sensitivity against PPARgamma than do other commercial anti-PPARgamma antibody, and may constitute a profound contribution to the screening of PPARgamma ligands as well as the functional study of PPARgamma.

A simple ELISA for screening ligands of peroxisome proliferator-activated receptor-gamma.

Peroxisome proliferator-activated receptors (PPARs) are orphan nuclear hormone receptors that are known to control the expression of genes that are involved in lipid homeostasis and energy balance. PPARs activate gene transcription in response to a variety of compounds, including hypolipidemic drugs. Most of these compounds have high affinity to the ligand-binding domain (LBD) of PPARs and cause a conformational change within PPARs. As a result, the receptor is converted to an activated mode that promotes the recruitment of co-activators such as the steroid receptor co-activator-1 (SRC-1). Based on the activation mechanism of PPARs (the ligand binding to PPAR gamma induces interactions of the receptor with transcriptional co-activators), we performed Western blot and ELISA. These showed that the indomethacin, a PPAR gamma ligand, increased the binding between PPAR gamma and SRC-1 in a ligand dose-dependent manner. These results suggested that the in vitro conformational change of PPAR gamma by ligands was also induced, and increased the levels of the ligand-dependent interaction with SRC-1. Collectively, we developed a novel and useful ELISA system for the mass screening of PPAR gamma ligands. This screening system (based on the interaction between PPAR gamma and SRC-1) may be a promising system in the development of drugs for metabolic disorders.